Improve grammar in some comments.

net/disk_cache/backend_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdint.h>
 
 #include "base/files/file.h"
 #include "base/files/file_util.h"
 #include "base/metrics/field_trial.h"
 #include "base/run_loop.h"
@@ skipping 178 matching lines @@
     entry->Close();
 
   return rv;
 }
 
 void DiskCacheBackendTest::InitSparseCache(base::Time* doomed_start,
                                            base::Time* doomed_end) {
   InitCache();
 
   const int kSize = 50;
-  // This must be greater then MemEntryImpl::kMaxSparseEntrySize.
+  // This must be greater than MemEntryImpl::kMaxSparseEntrySize.
   const int kOffset = 10 + 1024 * 1024;
 
   disk_cache::Entry* entry0 = NULL;
   disk_cache::Entry* entry1 = NULL;
   disk_cache::Entry* entry2 = NULL;
 
   scoped_refptr<net::IOBuffer> buffer(new net::IOBuffer(kSize));
   CacheTestFillBuffer(buffer->data(), kSize, false);
 
   ASSERT_THAT(CreateEntry("zeroth", &entry0), IsOk());
@@ skipping 3596 matching lines @@
   // because that would advance the cache directory mtime and invalidate the
   // index.
   entry2->Doom();
   entry2->Close();
 
   DisableFirstCleanup();
   InitCache();
   EXPECT_EQ(disk_cache::SimpleIndex::INITIALIZE_METHOD_LOADED,
             simple_cache_impl_->index()->init_method());
 }